Reconstructing an Architecture

Why Lost documentation No documentation ever Architectural drift Prove conformance

Approaches Manual Methods Top down Bottom up Opportunistic Tools

Tool-Based Reconstruction System Tool-Based Reconstruction Reconstruction Pattern Recogn. View Extraction Visualization DB Doc Presentation View Fusion

Data Source Types Static Dynamic

Tools Parsers Abstract Syntax Tree Analyzers Lexical Analyzer Profilers Code instrumentation tools Ad hoc Workbench

Extracted Data <includes file file> <contains file function> <defines_var file variable> <contains directory directory> <contains directory file> <calls function function> <access_read function variable> <access_write function variable>

Guidelines Use least-effort Validate the information extracted Extract dynamic information when needed

Tool-Based Reconstruction System Tool-Based Reconstruction Reconstruction Pattern Recogn. View Extraction Visualization DB Doc Presentation View Fusion

Database Structure Need a standard format or model Efficient queries Authors use Rigi Standard Format Efficient queries Support fusion Checkpointing for intermediate results

DB tables Table of relation names Table of elements Table for each relation - triples RelationTable RelationType Thing1 Thing2 And/Or IncludesTable File1 File2 ContainsTable File Function …

Tool-Based Reconstruction System Tool-Based Reconstruction Reconstruction Pattern Recogn. View Extraction Visualization DB Doc Presentation View Fusion

View Fusion Reconcile Augment Establish connections

Example: fusing static and dynamic views of the “calls” relation Static: calls extracted from source List::length PrimitiveOp::Compute Dynamic: calls detected by profiler List::getnth ArithmeticOp::Compute StringOp::Compute What about these? Static analyzer missed this (no reason given)

Fusing static+dynamic, continued PrimitiveOp +Compute Static analyzer saw this Profiler saw these ArithmeticOp +Compute StringOp +Compute Fused list of calls: See examples 10-4, 10-5 p 240 List::length List::getnth PrimitiveOp::Compute

Example: fusing calls from different processes main() { register(); } Server main() { launch(); } GUI Launcher Unfused Fused Calls Calls main register launch Server.main register Launcher.main launch

Guidelines for Fusions When no single view shows needed information When a view is too ambiguous and ambiguity can be resolved by fusion Use multiple extraction techniques Different kinds of tools Different implementations of tools

Tool-Based Reconstruction System Tool-Based Reconstruction Reconstruction Pattern Recogn. View Extraction Visualization DB Doc Presentation View Fusion

Reconstructions SQL examples for Reconstructions See 10.9 – aggregate local variables Build SQL queries for reconstruction

Guidelines Work with the architect if possible Code segments should be effective at producing new and useful view Naming conventions Directory structure

Example in text Repeated view fusions and aggregations eventually produce a just-barely-usable view pp 248 – 257